TRANSFORMING GROWTH-FACTOR-BETA AND BONE MORPHOGENETIC PROTEIN-2 FOR BONE INGROWTH - A COMPARISON USING BONE CHAMBERS IN RATS

We compared the ability of transforming growth factor beta 1 (TGF beta 1) and bone morphogenetic protein 2 (BMP-2) to increase the penetrati on distances for fibrous tissue and bone into porous coralline hydroxy apatite, Forty-four rats received pairs of titanium bone chambers impl anted bilaterally in their proximal tibiae. These chambers allow tissu e ingrowth from one end of a long cylinder, so that ingrowth distances along the cylinder axis can be measured, Since bone never grows as fa r as fibrous or undifferentiated mesenchymal tissue, we measured both total tissue ingrowth and bone ingrowth distances, All chambers were i mplanted with cylinders of porous hydroxyapatite (Interpore 200), The hydroxyapatite cylinders were treated with either 1, 33, or 1000 ng of TGF beta 1 or BMP-2 prior to implantation, and compared with untreate d contralateral control implants at 6 weeks, The bone ingrowth distanc e into the porous hydroxyapatite showed a trend toward inhibition with TGF beta 1 as compared to untreated controls (p < 0.08), and there wa s a negative correlation between TGF beta 1 dose and ingrowth distance s for both bone (p < 0.01) and total tissue (p < 0.01), BMP-2 greatly increased bone (p < 0.001) and total tissue (p < 0.001) ingrowth dista nces. (C) 1996 by Elsevier Science Inc.